CN113316631A

CN113316631A - Method and system for improving recovery rate of essential oil

Info

Publication number: CN113316631A
Application number: CN201980088240.2A
Authority: CN
Inventors: 凯莉·亨格斯; 约翰尼·卡萨诺瓦斯; 尼尔·格德曼
Original assignee: Tropicana Products Inc
Current assignee: Tropicana Products Inc
Priority date: 2019-01-07
Filing date: 2019-11-21
Publication date: 2021-08-27
Also published as: MX2021008220A; US20200216776A1; US10995300B2; CA3117693A1; WO2020146053A1; AU2019421469A1; BR112021007524A2; EP3908645A1

Abstract

Methods and systems for extracting essential oils from materials are described. The method comprises extracting essential oil into water to form a fluid mixture comprising essential oil, an essential oil-water emulsion, and water; heating the fluid mixture to destabilize the essential oil-water emulsion and separating the heated fluid mixture into a waste mixture and a product fluid mixture, wherein a concentration of the essential oil in the product fluid mixture is greater than a concentration of the essential oil in the fluid mixture.

Description

Method and system for improving recovery rate of essential oil

This application claims priority from U.S. application No. 62/789,002 filed on 7/1/2019, the entire contents of which are incorporated herein by reference.

The present disclosure relates to methods and systems for increasing recovery of essential oils.

Background

Essential oils (also known as essential oils) are present in plant, algae and animal matter and are extracted for use in food manufacture, pharmaceuticals, animal feed, cosmetics, fragrances, chemicals, and the like. A known method of recovering oil is to extract the oil from the material and capture the oil in water to produce a thin mixture or emulsion containing about 1% oil by volume. The thin mixture or emulsion is then fed to a deslagging centrifuge that removes most of the insoluble solids and concentrates the oil emulsion into a cream. The cream is then sent to a finishing centrifuge that seeks to break the emulsion to produce a finished essential oil product.

Unfortunately, the cream sent to the finishing centrifuge is typically a very viscous oil-water emulsion that is difficult to break, resulting in inefficiencies due to the loss of large amounts of the essential oil required. In addition, the pump produces a shear mixing action that reduces the size of the suspended oil droplets, effectively stabilizing the emulsion and reducing the recovery efficiency when transferring the cream to the finishing centrifuge. In other words, it is difficult to separate essential oils from stable emulsions. Thus, there is a need for a method of increasing the recovery of a desired essential oil.

Disclosure of Invention

According to one aspect of the present disclosure, a system for increasing recovery of essential oils is described. The system comprises: an extractor that extracts essential oil from an essential oil containing material into water to form a first fluid mixture containing an emulsion of essential oil (an essential oil-water emulsion); one or more separators that separate the essential oil from the first fluid mixture to form a second fluid mixture containing a higher concentration of the essential oil than the concentration of the essential oil in the first fluid mixture; means for heating the second fluid mixture to destabilize the emulsion and reduce the fluid viscosity of the emulsion; one or more separators that separate the essential oil from the second fluid mixture to form a third fluid mixture containing a higher concentration of the essential oil than the concentration of the essential oil in the second fluid mixture. The third fluid mixture may be considered a finished product suitable for packaging. In one embodiment, the system may further comprise means for reducing the temperature of the third fluid mixture. In another embodiment, one or more separators may be provided downstream of the third fluid mixture to separate the essential oil from the third fluid mixture to form a substantially pure essential oil having an essential oil concentration greater than the essential oil concentration in the third fluid mixture.

According to another aspect, a method or process for increasing recovery of essential oils is disclosed. The method includes extracting an essential oil from an essential oil containing material into water to define a first fluid mixture containing an essential oil emulsion. The first fluid mixture may also include solids, proteins and other components of the material source (e.g., plant material).

In this regard, the source of material can be any plant, algae, and/or animal matter that contains essential oils. However, it should be understood that the described process is applicable to increasing the recovery of essential oils from any material. In some aspects, the material is an edible plant, such as a fruit or vegetable. In certain aspects, the fruit may include, but is not limited to, Rutaceae (Rutaceae family) fruits such as oranges, lemons, grapefruits, limes, oranges, tangerines, which may be referred to as citrus fruits. In some embodiments, the essential oil is extracted from the peel of a citrus fruit.

The method also includes separating the first fluid mixture to produce a second fluid mixture comprising a mixture of essential oil, an essential oil-water emulsion, and water. The first fluid mixture has a first concentration of essential oil and the second fluid mixture has a second concentration of essential oil that is greater than the first concentration of essential oil. The method further comprises the following steps: heating the second fluid mixture to destabilize the essential oil-water emulsion, and separating the heated second fluid mixture to produce a third fluid mixture. The third fluid mixture has a third concentration of essential oil that is greater than the second concentration of essential oil.

In some embodiments, the method includes heating the second fluid mixture, separating the essential oil to form a third fluid mixture, and reducing the temperature of the third fluid mixture. In some embodiments, the method includes heating the second fluid mixture to a temperature above the flash point of the one or more essential oils, separating the essential oils to form a third fluid mixture, and reducing the temperature of the third fluid mixture to a temperature below the flash point of the one or more essential oils. The third fluid mixture may comprise from about 91% to about 97% (wt/wt) essential oil and may be suitable as a finished product (i.e., may be packaged for use).

In one embodiment, the cooled third fluid mixture is sent to a third separator to produce a fourth fluid mixture having a fourth concentration of essential oil that is greater than the concentration of essential oil in the third fluid mixture. The fourth fluid mixture comprises from about 91% to about 97% (wt/wt) essential oil, which can be considered a substantially pure essential oil.

In one embodiment, the substantially pure essential oil may exhibit a specific gravity of from about 0.83 to about 0.86, or from about 0.0835 to about 0.85, or about 0.845 at 25 ℃.

All percentages in this disclosure are by weight unless explicitly stated otherwise.

Drawings

The following description is accompanied by the figures, all of which are given by way of non-limiting example, and help to understand how the described methods and systems can be implemented.

This patent or application document contains at least one drawing executed in color.

Figure 1 is a simplified schematic of a system for increasing recovery of essential oils.

Figure 2 is a simplified schematic of another system for increasing essential oil recovery.

FIG. 3 is a perspective view of an exemplary oil extractor that may be used in one embodiment of the system shown in FIG. 1.

FIG. 4 is a perspective view, partially in cross-section, of an exemplary separator that can be used in one embodiment of the system shown in FIG. 1.

Fig. 5 is a front view of a portion of the separator shown in fig. 4.

Fig. 6 is a simplified schematic of a portion of a system that may be used to enhance the separation of essential oils from an emulsion and that may be used in the system shown in fig. 1.

Fig. 7 is a simplified schematic of a system for extracting or releasing essential oils from food material.

Figure 8 graphically depicts the reduction or decrease of the essential oil-water emulsion in a mixture as the temperature of the mixture increases, wherein the mixture comprises the essential oil, the essential oil-water emulsion, and water.

Figure 9 provides a series of photographs illustrating the reduction of essential oil-water emulsion in a mixture as the temperature of the mixture increases, wherein the mixture comprises essential oil, essential oil-water emulsion, and water.

Detailed Description

Referring now to fig. 1, a system 10 for increasing recovery of essential oils is shown. The system 10 is configured to extract essential oils from a starting material 12 and may be included as part of a larger system that processes the starting material. As described in more detail below, the system 10 utilizes thermal treatment to increase the efficiency of the system in separating essential oil from an essential oil-water emulsion.

As previously mentioned, the starting material 12 can be any plant, algae and/or animal material that contains essential oils. It should be understood that the described systems and methods are applicable to increasing the recovery of essential oils from any material. In some aspects, the starting material 12 is an edible plant, such as an edible fruit or vegetable. In certain aspects, the fruit may include, but is not limited to, fruit of the rutaceae family (also commonly referred to as the citrus family), which may be, for example, orange, lemon, grapefruit, pomelo, lime, tangerine (mandarin), small tangerine (clementine), which may be referred to herein as citrus fruit. In some embodiments, the essential oil is extracted from the peel of a citrus fruit.

The system 10 includes a fine oil extractor 20, the fine oil extractor 20 illustratively configured to process the starting material 12. Extractor 20 has an inlet 22, an outlet 24, and an outlet 26, from which outlet 24 waste and remaining starting materials may be directed for further processing, outlet 26 containing a first fluid mixture. The starting material 12 is delivered to an inlet 22 of the essential oil extractor 20 by a conveyor 14 or any suitable delivery device. The conveyor 14 is suitably configured to complement the starting material 12 to effectively deliver the starting material 12 to the inlet 22.

The extractor 20 is configured to extract the essential oil in the presence of water to provide a first fluid mixture containing the essential oil, the dilute essential oil-water emulsion, and water. Extractor 20 may be any suitable device configured to extract essential oils from starting material 12. Typically, the first fluid mixture contains from about 0.1% to about 5% essential oils, or from about 0.5% to about 3.5%, or from about 0.5% to about 1.5%, or about 1% essential oils.

Extractor 20 includes an outlet 24 through which outlet 24 few of the starting material 12 remaining in essential oil concentration is delivered for further processing or disposal. The extractor 20 further comprises an outlet 26, through which outlet 26 the first fluid mixture exits the extractor 20. It should be understood that the phrase "fluid mixture" refers to mixtures comprising a fluid or a liquid as well as mixtures comprising a fluid and a solid or partially solid material.

Downstream of the extractor 20, a tank (not shown) may be provided to collect the first fluid mixture. Alternatively, as shown in fig. 1, a separator 30 is provided to receive the first fluid mixture from the extractor 20. The separator 30 separates the first fluid mixture into three portions, a waste fluid mixture, a recycle fluid and a second fluid mixture. Accordingly, the separator 30 includes an inlet 32, a first outlet 34, a second outlet 36, and a third outlet 38.

Separator 30 may be any suitable separation device configured and effective to separate essential oil from the starting material solids and water. The separated starting material (waste fluid mixture), which may include starting material solids and water, is directed through outlet 38 for further processing or disposal.

A recirculation fluid containing less than about 0.5% essential oils or less than about 0.1% essential oils is directed through outlet 36 and recirculated to extractor 20. The second fluid mixture is directed through outlet 34 for storage or further processing.

The inlet 32 is fluidly connected to (or in fluid communication with) the outlet 26 of the extractor 20 via one or more conduits 11. It should be understood that one or more pumps (not shown) may be connected to conduit 11 to move the fluid mixture from extractor 20 to separator 30. It should also be understood that in other embodiments, the inlet 32 of the separator 30 may be connected to a tank or other storage vessel (not shown) that stores the fluid mixture until the separator 30 is ready to receive the fluid mixture.

Referring now to fig. 4, in one embodiment, the separator 30 is shown as a centrifuge including an outer shell 50 and an inner shell 52. One skilled in the art will appreciate that the centrifuge may be configured in any suitable manner such that the centrifuge effectively separates the materials. However, for simplicity, an exemplary centrifuge will be described. Inner shell 52 is tapered, extends from a lower base 54 to a narrow upper tip 56, and defines a chamber 58 configured to receive the first fluid mixture. Separator 30 includes a feed tube 60, which feed tube 60 is connected to inlet 32 and extends to a lower end 62 located within chamber 58. The feed tube 60 extends coaxially with a discharge tube 64 extending between the chamber 58 and the outlet 36. A further discharge tube 66 extends coaxially with the

tubes

60, 64 between the chamber 58 and the outlet 38.

The separator 30 includes a plurality of plates 70 located in the chamber 58 and configured to rotate within the housing 52. In the illustrated embodiment, the plate 70 is coupled to a drive shaft 72 that extends upwardly from a motor (not shown) located below the inner housing 52. Each plate 70 is conical in shape and, as shown in fig. 5, defines a number of channels 74 between the plates 70. Each channel 74 extends from an open upper end 76 adjacent the lower end of the discharge tube 64 to an open lower end 78.

The separator 30 also includes an annular outer passage 80 extending around an outer wall 82 of the housing base 54. As shown in fig. 4, the passage 80 is connected to the outlet 38 of the centrifuge. A number of doors (not shown) are located in the outer wall 82 to selectively connect the passageways 80 with the chamber 58 to allow removal/discharge of solid waste material from the chamber 58.

In use, a first fluid mixture comprising essential oil, a dilute essential oil-water emulsion, water and starting material is fed through inlet 32 along feed line 60 into chamber 58 of centrifuge 30. The plate 70 is rotated by a drive shaft to separate the first fluid mixture into lighter and heavier components. The lightest phase of the first fluid mixture is maintained near the upper end 76 of the channel 74 in a region 84 near the axis of rotation of the centrifuge 30. This lightest phase is called the second fluid mixture and comprises essential oil, an essential oil-water emulsion, water and a small amount of solid particles. The second fluid mixture is directed out of the separator 30 through an outlet 34. Typically, the essential oil is present in the second fluid mixture at a concentration of from about 40% to about 95%, or from about 60% to about 90%, or from about 70% to about 87%, or from about 75% to about 85%.

The heaviest phase of the first fluid mixture, which may include starting material waste, solids, and water, is drawn by centrifugal force to an outer wall 82 of the shell 52 adjacent the annular outer passage 80. The separator 30 periodically opens the door to connect the passageway 80 to the chamber 58 to flush such material from the separator 30 through the outlet 38 for further processing or disposal. It will be appreciated that the heaviest phase of the first fluid mixture exiting the outlet 38 may include a quantity of essential oils that may be directed for further processing.

A third phase of the fluid mixture, which comprises primarily water and may include fine solids, moves toward the lower end 78 of the passage 74. This phase exits centrifuge 30 through outlet 36 and returns to extractor 12 as a recycle fluid used in extractor 12. It should be understood that the mesophase of the fluid mixture (the recycle fluid) may contain a quantity of essential oil that is also recycled to the extractor 12.

Returning to fig. 1, the system 10 includes a heater 90, the heater 90 having an inlet 92, the inlet 92 being fluidly connected to the outlet 34 of the separator 30 via one or more conduits 13. It should be understood that one or more pumps (not shown) may be connected to conduit 13 to move the fluid mixture from separator 30 to heater 90. It should also be understood that in other embodiments, the inlet 92 of the heater 90 may be connected to a tank or other storage vessel (not shown) that stores the fluid mixture from the separator 30 until the heater 90 is ready to receive the fluid mixture. The heater 90 is operable to heat the second fluid mixture as it travels from the inlet 92 to the outlet 94 thereof. In one embodiment, the heater 90 is a shell and tube heat exchanger that uses a hot fluid (e.g., water) to heat the second fluid mixture.

The heater 90 is operable to heat the second fluid mixture to a temperature effective to break the essential oil-water emulsion and drive the essential oil out of the essential oil-water emulsion so that the essential oil can be recovered. Typically, the second fluid mixture is heated to a temperature of from about 30 ℃ to about 90 ℃, or from about 35 ℃ to about 70 ℃, or from about 35 ℃ to about 50 ℃, or from about 35 ℃ to about 45 ℃, or about 40 ℃.

In some embodiments, the second fluid mixture is heated to a temperature above the flash point of the one or more essential oils present in the second fluid mixture. In this regard, the skilled artisan will appreciate that each essential oil has a flash point. For example, grapefruit essential oil has a flash point of about 43 ℃ to 45 ℃, lemon essential oil has a flash point of about 48 ℃, and orange peel essential oil has a flash point of about 50 ℃. In those instances where the second fluid mixture is heated to a temperature equal to or above the flash point of the essential oil, the separator 30 may be hermetically sealed or sealed with a nitrogen blanket.

In other embodiments, the heater 90 may be operable to heat the fluid mixture to an elevated temperature slightly below the flash point of the essential oil to eliminate the need for a hermetic seal or a nitrogen blanket. For example, in some embodiments, the second fluid mixture is heated to a temperature of about 3 ℃ to about 7 ℃ below the flash point temperature of the essential oil, or about 5 ℃ below the flash point of the essential oil.

For example, if the essential oil is orange peel oil, the flash point is about 50 ℃. Thus, the second fluid mixture may be heated to a temperature of about 43 ℃ to about 47 ℃, or the second fluid mixture may be heated to a temperature of about 45 ℃.

Returning to fig. 1, a separator 100 is located downstream of the heater 90. Separator 100 may be any suitable separation device effective to separate the essential oil from the second fluid mixture to form a third fluid mixture having a higher concentration of essential oil than the second fluid mixture. In one embodiment, the separator 100 is a centrifugal separator, i.e., a centrifuge.

The separator 100 includes an inlet 102, the inlet 102 being fluidly connected to the outlet 94 of the heater 90 via one or more conduits 15. It should be understood that one or more pumps (not shown) may be connected to conduit 15 to move the second fluid mixture from heater 90 to separator 100. The separator 100 also includes a first outlet 104 and a second outlet 106, the first outlet 104 being in fluid communication with an inlet 112 of a cooler 110, the second outlet 106 directing the waste stream for further processing or disposal.

In one illustrative embodiment, the separator 100 has a configuration similar to the separator 30 described above. In use, the heated second fluid mixture enters the chamber 58 of the separator 100 through the inlet 102 along the feed pipe 60. The second fluid mixture is then separated into lighter and heavier components by the rotation of the plate 70. The lighter phase of the second fluid mixture is maintained near the upper end 76 of the channel 74, in a region 84 near the center of the chamber 58. This portion of the second fluid mixture comprises a substantial portion of the essential oil and a small amount of the essential oil-water emulsion and water and is referred to as the third fluid mixture. The third fluid mixture exits the separator 100 through an outlet 104.

In some embodiments, the third fluid mixture is directed into a tank (not shown) to be stored for further processing. In other embodiments, the third fluid mixture is directed to a separator 120 located downstream.

The concentration of the essential oil in the third fluid mixture is greater than the concentration of the essential oil in the second fluid mixture. Typically, the concentration of essential oil in the third fluid mixture is greater than about 80%, and may be from about 80% to about 97%, and may be from about 91% to about 97%, or about 95%. Such essential oils may be considered finished products and may be packaged for commercial use.

The heavier phase of the second fluid mixture, which may include fine solids and water, moves toward the lower end 78 of the channel 74. The phase exits the separator 100 through an outlet 106 for further processing. This phase may include some minor amounts of essential oils which may be recovered in further processing.

Advantageously, it has been found that heating the second fluid mixture increases the separation efficiency of the separator 100 relative to the fluid mixture at ambient or unheated temperatures. Without being bound by any particular theory, it is believed that the elevated temperature reduces the viscosity of the second fluid mixture, which allows for more efficient separation or dissociation of the essential oil from the essential oil-water emulsion.

Furthermore, it is believed that the elevated temperature may affect other components that may be present in the second fluid mixture. For example, the starting material may comprise one or more proteins that may denature at the elevated temperature generated by heater 90. Denaturation of the protein will beneficially facilitate destabilization of the essential oil-water emulsion to more effectively separate the essential oil from the essential oil-water emulsion present in the second fluid mixture.

Returning to fig. 1, a cooler 110 may be disposed downstream of the separator 100 to reduce the temperature of the third fluid mixture. The cooler 110 is particularly useful when the second fluid mixture is heated to a temperature above the flash point of the one or more essential oils. The cooler 110 has an inlet 112, which inlet 112 is fluidly connected to the outlet 104 of the separator 100 via one or more conduits 17. It should be understood that one or more pumps (not shown) may be connected to conduit 17 to move the third fluid mixture from separator 100 to cooler 110. It should also be understood that in other embodiments, the inlet 112 of the cooler 110 may be connected to a tank or other storage vessel (not shown) that stores the third fluid mixture from the separator 100 until the cooler 110 is ready to receive the fluid mixture. The cooler 110 is operable to cool the third fluid mixture as the fluid mixture travels from the inlet 112 to the outlet 114 of the cooler 110.

In one embodiment, cooler 110 is a shell and tube exchanger that uses a cold fluid (e.g., water) to cool the third fluid mixture. In those instances where the second fluid mixture is heated to a temperature above the flash point, the cooler will cool the third fluid mixture to a temperature below the flash point of the one or more essential oils.

The cooler 110 is operable to cool the third fluid mixture to a temperature of about 50 ℃ or less, such as about 40 ℃, or about 30 ℃, or about 25 ℃. In those instances where the second fluid is heated to a temperature at or above the flash point of the essential oils, the cooler will reduce the temperature of the third fluid mixture to a temperature below the flash point of the one or more essential oils.

The cooled third fluid mixture may be connected to a tank or other storage vessel (not shown) to store the cooled third fluid mixture for further processing, such as by directing the stored cooled third fluid mixture to a separator (e.g., separator 120). Alternatively, the cooled third fluid mixture may be directed to a packaging station where the third fluid mixture is packaged into containers.

In one embodiment, as shown in fig. 2, the separator 120 may be fluidly connected to the outlet 114 of the cooler 110. Separator 120 may be any suitable separation device effective to separate the essential oil from the third fluid mixture to form a fourth fluid mixture having a higher concentration of the essential oil than the third fluid mixture. In one embodiment, the separator 120 is a centrifugal separator, i.e., a centrifuge.

The separator 120 is configured to receive the third fluid mixture from the cooler 110 and includes an inlet 122, the inlet 122 being fluidly connected to the outlet 114 of the cooler 110 via one or more conduits 19. Separator 120 includes a first outlet 124 and a second outlet 126, with product essential oil exiting first outlet 124 and a few fluids of essential oil remaining exiting second outlet 126 for further processing.

In one illustrative embodiment, the configuration of the separator 120 is similar to the configuration of the

separators

30, 100 described above. In use, the cooled third fluid mixture enters the chamber 58 of the centrifuge 100 through the inlet 122 along the feed tube 60. The third fluid mixture is then separated into lighter and heavier components by rotation of the plate 70.

The lighter phase of the fluid mixture is maintained near the upper end 76 of the passage 74 in a region 84 near the center of the chamber 58. This portion of the third fluid mixture exits the separator 120 through the outlet 124 and is referred to as a fourth fluid mixture. The fourth fluid mixture (which may be referred to as the finished product) contains the highest concentration of essential oil and is substantially pure essential oil.

The concentration of the essential oil in the fourth fluid mixture is greater than the concentration of the essential oil in the third fluid mixture. Typically, the concentration of the essential oil in the fourth fluid mixture is from about 91% to about 97%, and can be about 95%, but in some cases the concentration of the essential oil can be from about 97% to about 99%, or higher.

The heavier phase of the third fluid mixture, which may include fine solids and water, in the separator 120 moves toward the lower end 78 of the channel 74. The phase exits the separator 120 through an outlet 126 for further processing.

It should be understood that in other embodiments of the system 10, the cooler 110 and the separator 120 may be omitted from the system 10 and the third fluid mixture from the separator 100 may enter a storage vessel or tank (not shown) for further processing, such as packaging.

Further, while the use of a heater is described as being located downstream of the first separator 30, it is contemplated that a heater (not shown) may be located downstream of the extractor 20 and upstream of the first separator 30. This arrangement, while feasible, may not be as desirable as locating the heater downstream of the first separator 30, as the flow rate exiting the oil extractor 20 may be greater than the flow rate exiting the outlet 34 of the first separator 30, which would require a larger heat exchanger and more energy for the heating stream. Furthermore, providing the heated flow to the first separator 30 would necessarily mean that the temperature of the recycled fluid exiting the second outlet 36 would be higher than required for either extraction of oil and could affect juice quality.

In other embodiments, such as the embodiment shown in fig. 6, the system 10 may include an additional subsystem 130, the additional subsystem 130 including a heat exchanger 132, the heat exchanger 132 receiving the fluid mixture and heating the fluid mixture before the fluid mixture enters the separator 134. Separator 134 is similar to

separators

30, 100, and 120, and directs the fluid mixture of increased concentration of essential oil exiting separator 134 to heat exchanger 136 to cool the fluid mixture before it enters other components of system 10.

Heat exchangers

132 and 136 may be shell and tube heat exchangers.

The heat exchanger 132 may heat the fluid mixture to temperatures such as those described above in connection with the heater 90. Similarly, the heat exchanger 136 may cool the fluid mixture to temperatures described above in connection with the cooler 110.

It is also contemplated that the fluid in one or more of

lines

24, 38, 106, and 126 is directed to subsystem 130, particularly to the inlet of heat exchanger 132, such that the outlet from heat exchanger 136 is directed to

separator

100 or 120.

Those skilled in the art will appreciate that one or more subsystems 130 may be used in the system 10 shown in fig. 1. For example, the subsystem 130 may replace the cooler 110. Alternatively, the subsystem 130 may be located downstream of the separator 120. In yet another alternative, more than one subsystem may be provided in a sequential manner at suitable locations, for example in place of cooler 110 or downstream of separator 120.

In other embodiments, the system 10 may include additional equipment to flush the piping and equipment of the system 10. For example, it may be desirable to flush any remaining and/or stagnant essential oil from piping, heaters, coolers, heat exchangers, and/or separators between uses or in the event of a system shutdown. As described in more detail below, the system or subsystem 210 shown in fig. 7 may include such devices.

Referring now to fig. 7, a system or subsystem 210 for extracting essential oils is shown. System 210 may be included as a subsystem of system 10 described above or as a stand-alone system. Subsystem 210 includes a tank 212, tank 212 being sized to store a fluid mixture containing essential oils, water, and other materials, which may be produced by extractor 20 and/or separator 30, for example, as described above. The tank 212 is fluidly connected to a pump 214, the pump 214 operable to propel the fluid mixture from the tank 212 to the heater 90.

The heater 90 has an inlet 92 and an outlet 94, the inlet 92 being fluidly connected to an outlet of the pump 214 via one or more conduits 216, the outlet 94 being connected to the separator 100. The heater 90 is connected to a heater circuit 218, the heater circuit 218 including a pump 220 and a heater 222. In the illustrative embodiment, steam or hot water is used to heat the water moving through heater 222. Steam or hot water is propelled into the heater 90 to heat the essential oil fluid mixture with the heater 90 to a temperature as described above as it moves through the heater 90.

The separator 100 is configured to receive the heated essential oil fluid mixture from the heater 90 and separate the essential oil fluid mixture into a heavier phase and a lighter phase as described above. The lighter phase exits separator 100 through outlet 104 to cooler 132, while the heavier phase exits outlet 106 of separator 100 for further processing, such as waste collection (not shown) or further processing for recovering any essential oils present in the heavier phase.

The cooler 132 is configured to cool the fluid mixture exiting the separator 100 before it enters other components of the system 210. The cooler 132 may be a shell and tube heat exchanger that cools the fluid mixture to a temperature below the flash point of the one or more essential oils using a cold fluid (e.g., water from the cooling water tower 230). The fluid mixture with increased concentration of essential oils is then passed to outlet 232 for further processing.

As described above, the system 210 also includes equipment for flushing any remaining stagnant essential oil from the heat exchanger and/or separator between uses or in the event of a system shutdown. As shown in fig. 7, system 210 includes a valve 240 connected to conduit 216 between pump 214 and heater 90. Valve 240 is also connected to a water source (not shown). The system 210 includes another valve 242 connected to the outlet of the cooler 132, the inlet of the tank 212, and the outlet 232 of the system 210.

When a flush is required, the

pumps

214, 220 and heater 222 may be de-energized and valve 240 opened to allow water to enter the system 210. Check valve 244 prevents fluid from entering pump 214, just as check valve 246 prevents fluid from tank 212 from entering valve 240 during normal operation. The water passes through heater 90, separator 100 and cooler 132 to valve 242. Valve 242 is operated to connect the outlet of cooler 132 with the inlet of tank 212 so that the contents of system 210, which may contain stagnant essential oil (and other materials), are flushed from heater 90, separator 100 and cooler 132 and recycled to tank 212 for possible recovery when system 210 is restarted.

Alternatively, the water may pass through heater 90, separator 100, and may exit through line 106.

According to another aspect, a method or process for increasing recovery of essential oils is disclosed. Those skilled in the art will appreciate that the system 10 described above may be used to implement the described process for increasing recovery of essential oils. Furthermore, those skilled in the art will appreciate that the essential oil concentrations and temperatures of the various fluid mixtures described above will apply equally to the described processes, even though they may not be explicitly specified.

The process includes extracting an essential oil from a material into water to define a first fluid mixture. The first fluid mixture includes essential oils, essential oil-water emulsions, water, and may include solids, proteins, and other components of the material source. The oil may be extracted from the material in any suitable manner to efficiently obtain the essential oil from the material. Typically, the first fluid mixture contains from about 0.1% to about 5% essential oils, or from about 0.5% to about 3.5%, or from about 0.5% to about 1.5%, or about 1% essential oils.

The process also includes separating the first fluid mixture to produce a second fluid mixture comprising essential oil, an essential oil-water emulsion, water, and a small amount of solid particles. The separation may be achieved by a separator that effectively separates the essential oil from the other components of the first fluid mixture. In one embodiment, the separation may be accomplished using a centrifuge. The first fluid mixture has a first concentration of essential oil and the second fluid mixture has a second concentration of essential oil greater than the first concentration of essential oil. Typically, the essential oil is present in the second fluid mixture at a concentration of from about 40% to about 95%, or from about 60% to about 90%, or from about 70% to about 87%, or from about 75% to about 85%.

Then, the second fluid mixture is heated to destabilize the essential oil-water emulsion to release the essential oil from the essential oil-water emulsion, and then the heated second fluid mixture is separated to produce a third fluid mixture. In some embodiments, the second fluid mixture is heated to a temperature greater than about 30 ℃. It is understood that in other embodiments, the temperature is from about 30 ℃ to about 90 ℃. Typically, the second fluid mixture is heated to a temperature of from about 30 ℃ to about 90 ℃, or from about 35 ℃ to about 70 ℃, or from about 35 ℃ to about 50 ℃, or from about 35 ℃ to about 45 ℃, or about 40 ℃.

In some embodiments, the second fluid mixture is heated to a temperature above the flash point of the one or more essential oils. In this regard, the skilled artisan will appreciate that each essential oil has a flash point. For example, grapefruit essential oil has a flash point of about 43 ℃ to 45 ℃, lemon essential oil has a flash point of about 48 ℃, and a flash point of about 50 ℃. In those instances where the second fluid mixture is heated to a temperature equal to or above the flash point of the essential oil, the separator 30 may be hermetically sealed or sealed with a nitrogen blanket.

For example, if the essential oil is orange peel oil, the flash point is about 50 ℃. Accordingly, the second fluid mixture may be heated to a temperature of about 43 ℃ to about 47 ℃, or the second fluid mixture may be heated to a temperature of about 45 ℃.

The separation may be achieved by a separator effective to separate the essential oil from other components of the second fluid mixture to form a third fluid mixture. In one embodiment, the separation may be accomplished using a centrifuge. The third fluid mixture comprises a third concentration of essential oil that is greater than the second concentration of essential oil. Typically, the concentration of essential oil in the third fluid mixture is greater than about 80%, and may be from about 80% to about 97%, or may be from about 91% to about 97%, and may be about 95%.

In some embodiments, the process comprises reducing the temperature of the third fluid mixture. In some embodiments, the process comprises reducing the temperature of the third fluid mixture to a temperature below the flash point of the one or more essential oils, wherein the second fluid mixture is heated to a temperature of about the flash point of the essential oils. Thereafter, the cooled third fluid mixture is separated to produce a fourth fluid mixture containing a fourth concentration of essential oil that is greater than the concentration of essential oil in the third fluid mixture.

The separation may be achieved by a separator effective to separate the essential oil from other components of the third fluid mixture to form a fourth fluid mixture. In one embodiment, the separation may be accomplished using a centrifuge. Typically, the concentration of essential oil in the fourth fluid mixture is from about 91% to about 97%, and may be about 95%, but in some cases the concentration of essential oil may be from about 97% to about 99%, or higher, which may be considered a substantially pure essential oil.

Returning to fig. 1 and 2, it is contemplated that fluid flow from one or more or even all of

lines

24, 38, 106, and 126 (when present) may be directed to a heater (not shown) to heat fluid present in the flow directed to the heater to within the same temperature range as described for heater 90. The fluid exiting the heater may then be directed to the inlet 102 of the separator 100 to recover any essential oils that may be present in the fluid in

lines

24, 38, 106 or 126.

In light of the above description of the systems and processes, the following examples are provided to illustrate exemplary applications of the described systems and processes and are not intended to limit the claimed invention.

Example 1

The above system and process can be used to obtain essential oils from citrus peels, particularly orange peels. The system may include a peel oil extractor configured to process whole fruit, such as whole oranges. An exemplary Extractor can be a Brown Oil Extractor Model 6100, commercially available from Brown International Corporation, LLC. Alternatively, an exemplary extractor may be a JBT citrus juice extractor available from John Bean Technologies Corporation.

Fig. 3 schematically illustrates an exemplary Brown Oil Extractor comprising a roller bed 21 located between an inlet 22 and an outlet 26 of the Extractor 12 shown in fig. 1. The roller 21 is mechanically actuated to advance the oranges 14 located on the roller 21 to the outlet 24 for further processing, such as extraction of juice and pulp. The roller 21 includes a number of cutting heads, for example cutting heads 23, which cutting heads 23 pierce or pierce the surface of the orange peel (the exocarp or the outer peel) of the oranges 14 located on the roller 21 to release the orange peel oil into the circulating water stream.

It will be appreciated that oranges have varying degrees of fruit softness, which can cause some of the oranges to tear and become mixed with the circulating water stream. This introduces various soluble and insoluble fruit components into the circulating water stream, including orange pectin, hesperidin, proteins, solid particulates, etc., thereby forming a fluid mixture comprising orange peel oil, water and waste. The fluid mixture may then be processed in the manner shown in fig. 2 and described above by directing the fluid mixture to separator 30.

Example 2

Orange peel oil was extracted as described above in example 1. The fluid mixture is fed to a centrifuge to produce a peel oil enhanced fluid mixture containing three phases, i.e., peel oil, a peel oil-water emulsion, and water. The peel oil enhanced fluid mixture was heated to temperatures of 50 ℃, 60 ℃, 70 ℃, 80 ℃ and 90 ℃ and a reduction in the amount of peel oil-water emulsion (volume) was measured (hence, an increase in the amount of oil phase). As shown in fig. 8, the percent reduction in the peel oil-water emulsion present increased from about 22% to about 70% as the temperature increased from 50 ℃ to 90 ℃. In other words, as the temperature of the fluid mixture increases, the presence or amount of oil-water emulsion decreases. A visual depiction of the reduced level of peel oil-water emulsion present in the peel oil enhanced fluid mixture is shown in the photograph of fig. 9. Those skilled in the art will appreciate that increasing the temperature of the peel oil enhanced fluid mixture will increase the recovery of peel oil (essential oil).

While the concepts of the present disclosure are susceptible to various modifications and alternative forms, specific exemplary embodiments thereof have been shown by way of example in the drawings. It should be understood, however, that there is no intention to limit the concepts of the present disclosure to the specific forms disclosed; but rather, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

Claims

1. A method of recovering essential oils comprising the sequential steps of:

extracting an essential oil in the presence of water to form a first fluid mixture containing a dilute emulsion of the essential oil, the first fluid mixture having a first concentration of essential oil;

separating the first fluid mixture to produce a second fluid mixture comprising an essential oil-water emulsion and a waste component, the second fluid mixture having a second concentration of essential oil, the second concentration of essential oil being greater than the first concentration of essential oil;

heating the second fluid mixture to destabilize the essential oil-water emulsion; and

separating the heated second fluid mixture to produce a third fluid mixture having a third concentration of essential oil that is greater than the second concentration of essential oil.

2. The method of claim 1, wherein the heating comprises heating the second fluid mixture to a temperature above a flash point of the essential oil.

3. The method of any one of the preceding claims, wherein the heating comprises heating the second fluid mixture to a temperature of about 30 ℃ to about 90 ℃.

4. The method according to any one of the preceding claims, further comprising cooling the third fluid mixture to a temperature below the flash point of the essential oil.

5. The method of any of the preceding claims, wherein the second essential oil concentration is from about 40% to about 95% essential oil by weight.

6. The method of any of the preceding claims, wherein the third essential oil concentration is equal to or greater than about 80% by weight essential oil.

7. The method of claim 4, further comprising separating the cooled third fluid mixture to produce a fourth fluid mixture having a fourth concentration of essential oil that is greater than the third concentration of essential oil.

8. The method of claim 7, wherein the fourth essential oil concentration is equal to or greater than about 91% by weight essential oil.

9. The method of any of claims 1 to 6, further comprising:

heating the third fluid mixture to destabilize the essential oil emulsion and the several food components present in the third fluid mixture, and

separating the heated third fluid mixture to produce a fourth fluid mixture having a fourth concentration of essential oil that is greater than the third concentration of essential oil.

10. The method of claim 9, comprising heating the third fluid mixture to a temperature of about 30 ℃ to about 90 ℃.

11. The method of claim 10, further comprising cooling the fourth fluid mixture to a temperature of less than about 50 ℃.

12. A system for recovering essential oils, the system comprising:

a first separator configured to receive a first fluid mixture having a first concentration of essential oil and separate the first fluid mixture into a first waste mixture and a second fluid mixture having a second concentration of essential oil, the second concentration of essential oil being greater than the first concentration of essential oil;

a heat exchanger configured to heat the second fluid mixture to destabilize an essential oil-water emulsion present in the second fluid mixture, and

a second separator configured to receive the heated second fluid mixture and separate the heated second fluid mixture into a second waste mixture and a third fluid mixture, the third fluid mixture having a third concentration of essential oil, the third concentration of essential oil being greater than the second concentration of essential oil.

13. The system of claim 12, further comprising:

a second heat exchanger configured to heat the third fluid mixture to destabilize an essential oil-water emulsion present in the third fluid mixture, and

a third separator configured to receive a heated third fluid mixture and separate the heated third fluid mixture into a third waste mixture and a fourth fluid mixture, the fourth fluid mixture having a fourth concentration of essential oil that is greater than the third concentration of essential oil.

14. The system of claim 12 or 13, further comprising:

a cooler configured to reduce a temperature of the third fluid mixture; and

a third separator downstream of the cooler and configured to separate the third fluid mixture into a third waste mixture and a fourth fluid mixture, the fourth fluid mixture having a fourth concentration of essential oil that is greater than the third concentration of essential oil.

15. The system of claim 12 or 13, wherein the heat exchanger is configured to heat the second fluid mixture to a temperature above a flash point of the essential oil.

16. The system of claim 15, further comprising a second heat exchanger fluidly connected to an outlet of the second separator and configured to cool the third fluid mixture to a temperature below a flash point of the essential oil.

17. A method of recovering an essential oil from an essential oil-water emulsion present in a first fluid mixture, the method comprising:

heating the first fluid mixture to destabilize the essential oil-water emulsion, the first fluid mixture having a first concentration of essential oil; and

separating the heated first fluid mixture into a waste mixture and a second fluid mixture, the second fluid mixture having a second concentration of essential oil, the second concentration of essential oil being greater than the first concentration of essential oil.

18. The method of claim 17, further comprising cooling the second fluid mixture.

19. The method of claim 17 or 18, wherein the heating is performed to raise the temperature of the first fluid mixture to a temperature above the flash point of the essential oil.

20. The method of claim 17 or 18, further comprising:

heating a second fluid mixture to reduce the viscosity of the second fluid mixture; and

separating the heated second fluid mixture into a waste mixture and a third fluid mixture having a third concentration of essential oil that is greater than the second concentration of essential oil.